Hitherto farmers have usually opened and closed sluice gates manually to release water from an impounded supply, distribution channel or the like onto land to be irrigated. The gates themselves have frequently comprised a closure element in the form of a flat leaf able to be raised or lowered bodily in upright guides at each side of a gateway, in the manner of a portcullis, to control flow through the gateway. In other instances swinging leaf gates analogous to conventional double doors have been used. It is also known to use portcullis type gates wherein the closure element is an arcuate leaf that swings up and down about a horizontal axis rather than sliding in guides as aforesaid.
It is known to use portcullis type gates wherein the closure element is a hollow body that may be filled with, and emptied of, water to assist in the lifting and lowering of same.